Task Group 101
Radiological Protection in Therapy with Radiopharmaceuticals

A Task Group under Committee 3

Radionuclide therapy combines the therapeutic effect of radiation with the targeting capability of molecular therapies and is increasingly being utilised as the result of ongoing development of various novel radionuclides, tracer molecules, and application techniques. Committee 3 established a working party (WP) on therapy with radiopharmaceuticals to assemble the previous guidance documents and new data in the literature and evaluate the need for providing recommendations related to radiological protection of patients and staff as well as of the environment. During this process, it became clear that establishment of a new framework of dosimetry as well as novel treatment approaches should be considered. Such a framework could include individual patient dosimetry to plan the therapy, test activities and pre-treatment tracers, measurement of whole body/tumour/organ kinetics, analysis of urine or blood samples, quantitative measurements of test and therapeutic activity, dose calculation based on 3D-patient images or patient-like phantoms using Monte-Carlo or analytical techniques, an evaluation of how to scale-up pre-treatment results to therapeutic activity levels, as well as new approaches for written directives for the therapy. The review also identified a need for additional guidance with regard to overall radiological protection practices, including protection of patients and staff, associated with this new approach.

It is particularly important to alert the community in variation of patient kinetics at therapeutic levels of activity. The medical community currently does not have easy access to biokinetic or dosimetric data for such approaches. In the vast majority of therapeutic modalities many treatments are effectively administered blind, quantitative imaging or dosimetry is seldom performed and ‘standardised’ or ‘nominal’ activities are employed. A collection and review of the existing information and literature in the context of therapeutic use will help optimise therapeutic use and protection required for radiopharmaceuticals, particularly for new treatment modalities, compounds, radionuclides and administration approaches. The introduction of new treatment procedures also requires additional guidance for radiological protection of staff, especially when multidisciplinary teams are involved (e.g. procedures in interventional catheterisation laboratories).

The first step is to continue assembling available data on these treatment modalities, compounds, radionuclides, biokinetics, and individual treatment planning approaches. Summarising these data and having intensive discussion among the experts of different fields will bring a consensus of how best to optimise therapeutic applications and the radiological protection practices required. On the basis of these approaches, new recommendations and radiological protection in therapy with radiopharmaceuticals will be established. Radiation protection and risk estimates for staff, carers, family, friends and the general public will be discussed after each treatment method as well in a specific chapter, where there will be a detailed description of occupational, general public and environmental issues connected to radiopharmaceutical therapy.

The present work will provide recommendations on optimising therapeutic applications (including new aspects of individual dosimetry in therapy with radiopharmaceuticals) and radiological protection practices to be published in the Annals of the ICRP (ca. 100 pages).  The target audience will be clinicians, staff, medical physicists, radiological protection officers, and regulatory authorities.

Yoshiharu Yonekura (Chair), National Institutes for Quantum and Radiological Science and Technology, Japan
Sren Mattsson (Honourary Co-Chair), Skne University Hospital Malm and Lund University, Sweden
Wesley E. Bolch (Member), University of Florida, USA
Lawrence T. Dauer (Member), Memorial Sloan-Kettering Cancer Center , USA
Chaitanya Divgi (Corresponding Member), USA
Mark Doruff (Corresponding Member), General Electric - Retired, USA
Darrell Fisher (Corresponding Member), Versant Medical Physics and Radiation Safety, USA
Glenn Flux (Member), UK
Makoto Hosono (Corresponding Member), Kindai University, Japan
Michael Lassmann (Corresponding Member), Germany
Stig Palm (Corresponding Member), Sweden
Pat Zanzonico (Corresponding Member), USA